Technically, to be excommunicated is to be denied access to the sacraments, so in dreams signifies being prevented from communicating with the divine n emotionally, to find ourselves excommunicated in dreams suggests being cut off from a source of comfort.
[1]Material aspects: As humans we have a strong need at times to belong to groups. When we dream of being excommunicated we must cope with feelings of rejection, and perhaps of disapproval.
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